Premature mortality in persons with epilepsy and schizophrenia: A population-based nationwide cohort study

Objective: To determine the mortality for persons with epilepsy and schizophrenia by absolute and relative measures.

Methods: This is a population-based nationwide cohort study of persons born in Denmark from 1960 to 1987 who were alive and residing in Denmark on their 25th birthday. We identified persons diagnosed with epilepsy and schizophrenia prior to their 25th birthday and followed them to death, emigration, or December 31, 2012, whichever came first. The primary outcome was overall mortality. Data were analyzed using Cox regressions.

Results: Persons were followed for 24 167 573 person years; the median was 15 years. The mortality rate ratio was 4.4 (95% confidence interval [CI] = 4.1-4.7) for persons with epilepsy, 6.6 (95% CI = 6.1-7.1) for persons with schizophrenia, and 12.8 (95% CI = 9.1-18.1) for persons with both disorders, compared with persons without these disorders. The estimated cumulative mortality at the age of 50 years was 3.1% (95% CI = 3.0-3.1) for persons without epilepsy and schizophrenia, 10.7% (95% CI = 9.7-11.8) for persons with epilepsy, 17.4% (95% CI = 16.0-18.8) for persons with schizophrenia, and 27.2% (95% CI = 15.7-40.1) for persons with both disorders.

Significance: Persons with epilepsy and schizophrenia have very high mortality; more than one in four persons with both disorders died between the age of 25 and 50 years, indicating that these patients need special clinical attention.